Browning's stance is no steel shot, regardless of size, through Belgium barrels. It can be found on their website.
EDIT; Here you go...
1. WILL ACCEPT ALL CURRENT FACTORY STEEL SHOT LOADS:
All Browning shotguns with the *Standard* *Invector, Invector-Plus *or* DS *choke* *tube systems, However, we do not recommend the use of Invector full or extra full chokes with steel shot. They pattern too tightly, and sometimes result in a "blown" pattern.
2. WILL ACCEPT ALL CURRENT FACTORY STEEL SHOT LOADS EXCEPT THOSE WITH T - BBB SIZE SHOT:
The B-2000 and B-80 shotguns with conventional chokes (Non-Invector)
3. DO NO USE ANY STEEL SHOT LOADS:
The Belgian-made A-5, Superposed, Leige, and other Belgian Over/Under models, Double Automatic, American-made A-5 and all other models not listed in category 1 or 2. Note: Belgian Auto-5 barrels are interchangeable with the new Invector barrels which are made in Japan. With this new Invector barrel installed on the Belgian-made Auto-5 receiver, steel shot loads can be used. (Shown below, Begian Superposed Over and Under.)
http://www.browning.com/customerservice/qna/detail.asp?id=128
------------------------------------------------
What Hank posted from Brownings website before.
http://duckboats.net/cgi-bin/forum/gforum.cgi?post=268968;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread